LOL sails again

This is the place to discuss your completed boats, and the practical sailing experience on them. What works, what doesn't? What do you want to change and what would you do differently next time?
Trisailor
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Joined: 27 Jan 2018, 23:46

Re: LOL sails again

Post by Trisailor » 28 Jan 2018, 01:31

Intrigued by your zipper luff laser sail. But first, good on you with your great little proa and adventurous spirit. Love your progression, experimentation, passion for reasoning and doing-it-my-way attitude. I suspect the mast bend, or lack thereof, with your new sails is the upwind inefficiency culprit. Those sails are cut full with quite a rake in the Luff to assist mast bend, so booms need to be ratcheted down to ensure good flat upwind shape - I think. Plus vangs upwind of course.

Currently sail a Cross 18 Trimaran though. Didn’t build her, but have modified her substantially for expedition sailing. Use a pop up cot tent on a side tramp for sleeping, or just lay down on the modified bed seat. Did the Texas 200 last year in her. Live in Utah, so quite a drive. Have all my little vids up on YouTube if interested. Four on the 2017 Texas 200 alone. For my videos search Cross 18 Trimaran. Her name is Crosswins.

Now, your sails. My exact idea for the tri I’m building. Will use a laser and had decided enlarged luff with zippers would work to allow reefing and lowering. Anyway, am building a 13’ x 10.5’ tri adapted from a 30 year old foam Snark. Raise gunnels, lengthened bow and widened stern. Will have a small open cuddly for storage. She’ll be an expedition boat for the T200 when Crosswins becomes more of a boat than I want to handle. Am 68. Bought a used laser mast and two new cheap laser practice sails thinking I could tinker with the luffs for raising, lowering by halyard. One is 4.7 the other a standard. Will decide on daily basis which one to raise depending on forecasts. Winds are high during Texas 200. Am not particularly concerned with tight upwind ability. The course is all (mostly) off wind. Right now am spoiled with Crosswins, she about sails directly into the wind!

Questions: Love to get in touch with your sailmaker for a quote. Nobody around here so have always had to ship my sails off anyway. But want someone who has already done what you had done (with any lesson-learned pointers from you) to work on mine. Second, could you share the cost per single sail and what that included? Third, did you all straighten out the luff curvature or leave the curvature in it?

BTW you are one lucky guy to have such a beautiful watery backyard to play in my man! Enjoy.
Trisailor
Posts: 2
Joined: 27 Jan 2018, 23:46

Re: LOL sails again

Post by Trisailor » 28 Jan 2018, 03:45

Greetings. New to this forum. Very interested in your zippered luff sleeve laser sails. Love your adventurous experimental spirit. Good on you buddy. Am building a small expedition tri and had same idea. Already have the laser mast and sail ready to go, but need a way to reef it and lower with halyard. Read everything you said about yours and realize it may loose some upwind pointing ability. That's OK. Would love to have additional pictures of the arrangement - close up off the mast. Plus, could you give me an idea what your mods cost and how to contact Bruno? Have always shipped my sails out for work anyway, so no big deal. Much appreciated. BTW, I sail a homebuilt tri - search Cross 18 Trimaran. Name is "Crosswins". Cheers.
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cpcanoesailor
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Joined: 03 Sep 2014, 13:35

Re: LOL sails again

Post by cpcanoesailor » 22 Apr 2018, 15:19

I finally took the winter cover off LOL yesterday. What a long, cold spring. I'm happy that the battery voltage didn't drop noticeably after 6 months without charging. I'll rig LOL in a week or so.
I got some of the projects on my list done over the winter, so now it's time to evaluate the results.
I've modified the trolling motor with a model airplane propeller with higher pitch than the original. I'm curious to see how that works.
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cpcanoesailor
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Joined: 03 Sep 2014, 13:35

Re: LOL sails again

Post by cpcanoesailor » 30 Apr 2018, 13:48

I tested a 11x6 propeller and spinner with the trolling motor. What a difference! For the same current draw, the boat goes 25% faster. I'm not seeing any cavitation at all from this prop. The stock 3 blade would cavitate occasionally. Mind you, this is at low speeds, but faster and easier than using the yuloh (sculling oar). Top speed tested was 3.8 knots at 12V, 35A.

The stock prop had a pitch of about 3.5, and was 9.5" diameter.

The new prop is a 11" diameter APC sport prop, which cost $5. The spinner cost $8.

With my 110W panel, which will provide >5A in full sun, I can run indefinitely at 1.5 knots, or more than 5 hours at 3 knots.

Geek phone vid: https://www.flickr.com/gp/12769215@N06/Z26w17

I plan to build a fin around the pipe shaft to reduce turbulents. That should improve efficiency even more.

Curtis
Last edited by cpcanoesailor on 01 May 2018, 13:05, edited 1 time in total.
Hans
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Joined: 13 Oct 2015, 19:51

Re: LOL sails again

Post by Hans » 30 Apr 2018, 17:31

Hello Curtis,
I went the same RC prop/spinner route as you did (did you read the info on boatdesign.net too ?), and for my small outrigger boat the results are about the same as yours.
When you make the fairing around the shaft, keep in mind that this fairing will act as a rudder/fin. Steering will be more difficult with the motor in the water. I learned this the the hard way by not being able to gibe/turn as quick as I was used to, collide at full speed with a barge and snapping off a float........

Cheers, Hans
RobinBennett
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Joined: 08 Feb 2015, 22:36

Re: LOL sails again

Post by RobinBennett » 30 Apr 2018, 21:43

Any idea what RPM it's running at, and the kV of the motor?

It's usually worth trying a variety of props on an RC plane to see what works best. If you're happy with the power draw, I'd try a 13x5 and a 11x7 to see what it's like in a lower or higher 'gear'. Also, I imagine that these props are a lot more fragile than the original, so it's worth carrying a spare.

Also, I guess you're running the prop behind the vertical shaft but it might be more efficient the other way around. RC planes with the prop on the back are always much louder than those with the prop on the front, as the low-pressure area in front of the blade causes noise as it chops past the obstruction. The extra noise is noticeable even when the gap is as big as the prop radius.
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Rob Zabukovec
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Joined: 27 Aug 2014, 21:20

Re: LOL sails again

Post by Rob Zabukovec » 30 Apr 2018, 23:30

Russell Brown is using a front of shaft prop setup on his latest pedal drive for R2AK 2018:

Advantages: more efficient and less noisy
Disadvantages: collects weed and can be damaged more easily

http://forums.sailinganarchy.com/index. ... 18/&page=6

Main raison d’etre for the new drive is so that it is more quickly deployable/retracted and more accessible than a drive through a hole in the cockpit floor, plus improved pedaling ergonomics. The drive train is more complicated however......

A suggestion which I made in that thread was to get oversized props and cut the tips off.... more blade area for a given diameter and more robust tips. I am trialing one on Sidecar at the moment.

Another thought Curtis, there is nothing stopping you trying three blade or even four blade model aeroplane props if you are constrained by diameter and water clearance?
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cpcanoesailor
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Joined: 03 Sep 2014, 13:35

Re: LOL sails again

Post by cpcanoesailor » 01 May 2018, 13:24

The fairing will be much smaller than the rudders, and the motor is toward the centre of the boat, so rotation shouldn't be a problem. But I will pay attention.

The motor draws at most about 40A, so I'd say it's a 480W motor. More blades will increase thrust, but reduce efficiency, so I'm happy with 2 blades and a slower start. The motor also folds up nicely against the side of the hull when sailing, so it won't be damaged if smacked hard by a wave on the quarter.

I need to get some spare props, since this is a puller, and I sail in wood infested waters. I went with a puller because the connecting shaft is very close to the prop, and there's not enough room to taper the fairing if the prop is pushing. Aside from turbulents along the shaft, it is very quiet.

I'll keep in mind the cut-down larger prop idea. They would me more robust than the 11", which is slim, but not delicate. The electric and slow-flier props looked delicate.

Sorry, I got confused about the size in the video and when posting. It's an 11" prop. Edited above.
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cpcanoesailor
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Joined: 03 Sep 2014, 13:35

Re: LOL sails again

Post by cpcanoesailor » 13 May 2018, 14:48

Yesterday was LOL's first sail of 2018. The conditions were varied from calm to some whitecaps and 15 knots. I got to practice reefing. As usual, LOL was great reaching and off wind, but struggled to make ground upwind and against the tide. And not super fast. Top speed recorded was 12km/h. I was tired from all that sheeting.

The motor worked well. It's almost silent at slower speeds, but vibration increases when pushing into the wind. The fairing project failed - the plastic shell blew open when I added the expanding foam, so I had to cut it all away. Oh well.

The trace shows only sailing. It starts in the middle, below the island, then proceeds north off wind. The squiggly part is shunting up wind and then bearing off toward the launch ramp. The longest, messy shunt is where I tied in the reefs.
Screen Shot 2018-05-13 at 7.33.19 AM.png
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cpcanoesailor
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Re: LOL sails again

Post by cpcanoesailor » 22 May 2018, 14:52

I had a dubious adventure this weekend. I planned to sail out of Vancouver Harbour, then around Bowen Island, and then return back through the harbour. Motoring out through the harbour was fine, and I was able to get part way toward Bowen, but then the wind died (just like last time). I decided to start motoring toward Bowen, but changed my mind part way there and instead ducked into a little cove in West Vancouver for the night. I had a nice night at anchor.

The next morning, I awoke to a gusty, contrary wind. The forecast seemed ok, and this wind was just a local phenomenon that would ease or switch to the expected direction. Then, when shifting the boat, I dropped my anchor line and lost the anchor. I repositioned using the other smaller anchor. I also dropped a knife through the slot between vaka and platform.

After waiting a while, I decided to venture out to check the conditions. There was a gusty wind of 10-15 knots, but the seas were not rough. Given my losses so far, and doubts about battery capacity, I decided to start heading back to the harbour. I managed to hoist the sails and tie in reefs, and started sailing for Spanish Banks on the south side of Burrard Inlet. I figured that with the Fraser River's high level, there would be a counter-current along the banks that would push me in the direction I wanted. After an hour the wind had steadied and I shook out the reefs.

The wind shifted a few times, but I was able to make proress east. Then it went light, so I thought I'd try the motor just to hold my position against the tide. Nothing. Battery and speed control seemed fine, but the prop didn't turn. I couldn't get the motor's head open, so I couldn't fix it. There was no way I could get through the harbour without the motor. For now, all I could do was to keep sailing for some place I could anchor and figure out what to do.

to be continued...
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